NEW YORK and CLEVELAND—A few days ago, Abeona Therapeutics Inc. announced one year data from Cohort 1 of the ongoing ABO-102 Phase 1/2 trial for Sanfilippo syndrome Type A (MPS IIIA), a rare autosomal-recessive lysosomal storage disease. The results demonstrated durable clinical effects achieved one year post-administration, with significant reductions in biopotency and biophysical measures, preservation of deep brain architecture and stabilization across multiple neurocognitive assessments, in comparison to untreated control subjects.

“Abeona continues to advance its world-leading gene therapy for MPS IIIA patients and we are excited about the updated results seen in Cohort 1 one year post-dosing. The observation of dose- and time-dependent responses in the CSF at 12 months provides strong additional support for our clinical approach, and comparison of data from six treated and fifteen control subjects supports the intravenous delivery approach for patients with a lysosomal storage disease. We are encouraged by the continued reductions in liver volumes, signs of brain architecture preservation and preliminary evidence of stabilized neurocognitive decline,” stated Timothy J. Miller, Ph.D., President and CEO of Abeona Therapeutics.

The ongoing Phase 1/2 clinical trial, which has received FastTrack designation, Orphan Product Designation and Rare Pediatric Disease designation by the U.S. Food and Drug Administration, is designed to evaluate safety and efficacy of ABO-102 in patients with MPS IIIA. The global clinical study is supported by a 25-subject MPS III Natural History Study, (Truxal et. al., 2016, Mol. Genet. Metab.), which included potential efficacy assessments consisting of neurocognitive evaluations, biochemical assays and MRI data generated over one year of follow-up assessments.

The ABO-102 (AAV-SGSH) trial involves a single intravenous injection of ABO-102 to deliver the AAV viral vector systemically throughout the body, in order to introduce a corrective copy of the gene which underlies the cause of the MPS IIIA disease. Subjects were evaluated at multiple points post-injection for safety assessments and initial signals of biopotency and clinical activity. Results indicate that ABO-102 successfully reached target tissues throughout the body, including in the central nervous system.

Highlighted data on three patients treated in Cohort 1 of the gene therapy trial compared to 8-15 control subjects included biopotency assessments, wherein ABO-102 demonstrated dose- and time-dependent durable reduction in the CNS of heparan sulfate (HS), the sugar molecule that is the hallmark of the disease. At one year post-injection, three patients in Cohort 1 demonstrated reduction of 69.3% +/- 5.7% (P<0.001) in cerebral spinal fluid (CSF) heparan sulfate.

Biophysical assessment showeddurable biophysical reductions of disease burden with reductions observed in liver volumes. Cohort 1 subjects demonstrated normalization of liver volumes of 80% (+/- 16.2%) points at one year (P<0.005) post-injection. The natural history study in 25 subjects with MPS III demonstrated that subjects had increased liver volumes averaging 220% at baseline that was maintained over a year of follow-up.

Preservation of key deep brain areas was observed. The initial analysis of Cohort 1 patient MRI data showed evidence of stabilization of area of deep brain architecture in the thalamus and putamen (P<0.05) at one year post-administration. Cognitive assessments at the 12-month time point for Cohort 1 showed evidence of stabilization in the Leiter-R non-verbal IQ (n=2) and Vineland (adaptive behavior) (n=3, P=0.05) scales.

ABO-102 was well-tolerated in all subjects through approximately 2,000 days cumulative post-injection. No drug-related serious adverse events were reported in subjects in the cohort receiving ABO-102 (Cohort 1: 5E12 vg/kg).

“We remain encouraged by signs of tolerability and biological effects that we have observed in Cohort 1 one year post-injection,” stated Juan Ruiz, MD, Ph.D., MBA, Chief Medical Officer, Abeona Therapeutics Inc. “Importantly, the stabilization of deep brain architecture at 1 year highlights the potential of intravenous route of delivery in accessing the basal ganglia to promote neural stabilization. We are pleased to see continued decreases in CSF HS in the Cohort one year post-administration, along with positive signs of neurocognitive and physical benefits at the low dose.”

“We look forward to accelerating enrollment with our active global sites in Spain and Australia and reporting additional clinical data from the ABO-102 global MPS IIIA trial later this year,” said Miller.